A variety of industries utilize raw water for steam generation, cooling and process water which has to be purified of colloidal matter such as clays, organics, etc. In turn, these industries generate vast quantities wastewater containing high concentrations of organics, oil emulsions, clay particulates, BOD and COD which has to be purified before it is returned to nature. Both the raw water and wastewater particulates are stabilized by a number of factors ranging from natural electrokinetic forces, solubilization, to high concentration of chemicals such as surfactants.
In recent years, the use of low molecular weight water-soluble polyelectrolytes has become quite popular in treating these waters. Conventional practices include chemistries such as polyethyleneamine, epichlorohydrin/dimethylamine and diallyldimethylammonium chloride. While diallyldimethylammonium chloride (DADMAC) polymers have proven effective and are claimed to be an industry standard, they are costly and must be used at high dosages. Furthermore owing to their high frequency of cationic charge distribution, their dosage window is rather narrow, resulting in poor runnability.
The idea for the synthesis of low molecular weight copolymers of DADMAC was generated due to the unique structural feature of polyDADMAC. It is known that the DADMAC monomer can be polymerized with the five-membered ring structure in the backbone with cationic pendant groups. These rings on the polymeric backbone impart ridity on the macromolecule, and the cationic pendant groups impart water solubility.
According to the application needs, if the rigid structure of polyDADMAC could be further modified to incorporate degrees of flexibility by copolymerization with suitable comonomers, an advance in the art would be offered.